green stems gone brown and begging to brown on leaves? DIYING??

hi people, another grow another problem I have not come across and would ike pointing out in the right direction if at all possible to fix my problem.

My cuttings are white rhino and cheese, been veg since 14th december. up untill yesterday I was running just one 600w veg and yesterday added another 600w to make total 1200w of veg on 24/0, temp 26c, Ph at 5.8 - 6.0, fed everyother day, first week ph 5.9 fed on tap water with 15ml of root stim, 3 days ago intorduced 10ml of canna coco A & B to the feed program.

Now my stems have become brown and looks tho its travelling up the stem onto the fan leaves. pics show









Are these diying, brown leaves fron the stem, thats not good...right?

All info appreciated

picture of phosphorus being locked out from cooler temps

is that air temp or water temp?

current temp air is 26c

does this phosphorus affect the stems also as my pics show?

bump, can anyone help please

Right ok been doing some work yesterday and this morning. Empty res. And flushed with 5.8 plain water at 20c. My run off was 6.5! After a week of using old ph meter it decided to not give me accurate readings even after re calibration. So got a new ph meter. I had to calibrated it with 4 and 7. So now touch wood the ph issue Will be sorted. Today i dumped the res water for some new ph 5.8 water.

How soon can i flush again? Can anyone tell me What's the optim water temp for my res? Also sorry about all the qs but if i wanted quickly bring my water temp up can i boil some water and add it or do i have to wait for the water heater to get the res up to temp?

Thanks for all input

You can flush in hydro as often as you want but I doubt you will need it. Your plants don't look that bad. Safe reservoir temp is 60-70 degrees with 68 being optimal IMO. As long as the boiling water is well mixed into the reservoir, I can't imagine that it would hurt anything

Ok cheers mate for info. My temp in water stumped me for a while. Forgot all about it. Plus with the ph being off got some probs with that also. Will do another flush soon as temps are up

Update. Checked on them this morning and now the leaves are going crisp. No doubt they Will fall off. I am feeding them right now water temp is 22c ph 5.9 added H202 40ml. A and b 50ml. Will upload pics once I've taken them and would like some feedback if at all possible. Starting to scratch my head on this









all help appreciated

at the mo I feel like ive lost all confidence in growing, been doing it a while now but never had this problem. part of me wants to start again but loosing 2 wks veg time I wanna sort it out and learn more.